1. Field of the Invention
This invention relates to cellulose food casings and more particularly to internal coatings for the casings which impart meat release characteristics and improve the strand strength properties of the casing.
2. The Prior Art
In the manufacture of regenerated cellulose sausage casings viscose is extruded through an annular die into a coagulating and regenerating bath to produce a tube of regenerated cellulose. The tube is subsequently washed, plasticized with glycerin, and dried while inflated under a substantial air pressure. After drying, the casing is wound on reels and subsequently shirred on high speed shirring machines, such as those described in U.S. Pat. Nos. 2,010,626; 2,583,654; 2,722,714; 2,722,715; 2,723,201 and 3,451,827. In the shirring process, lengths of from 40-200 feet of casing are compacted into strands of a few inches, e.g., 4-30 inches. The shirred casing strands are packaged and sold to the meat processor wherein the casings are stuffed with a meat emulsion, the meat cooked, and the casing removed from the meat processed therein with high speed peeling machines.
It has been proposed to lubricate and internally humidify cellulose casings on a shirring machine by spraying a mist of water and a stream of lubricant through the shirring mandrel to increase the flexibility of the casing and to prevent casing film breakage, referred to in the art as "pinholing". Lubricants typically used in the shirring operation for aiding and assisting passage of the casing over the shirring mandrel include food grade vegetable, mineral, or silicone oils.
Recently it has been proposed (e.g., U.S. Pat. No. 3,898,348) to coat the internal surfaces of cellulose sausage casings with a homogeneous admixture of a water-soluble cellulose ether and an additive selected from animal, vegetable, mineral and silicone oils and alkylene oxide adducts of partial fatty acid esters. The coating is applied to the casing surface in a proportion such that the additive is present in a proportion of at least 0.1 times the weight of the water-soluble cellulose ether but no more than 0.5 mg. per square inch of casing surface.
Casings coated with the meat release coating compositions of U.S. Pat. No. 3,898,348, although exhibiting excellent peelability characteristics have deficient strand strength characteristics, i.e., the strand is fragile and tends to break on doffing or when the strand is stuffed.